The leaflet that came with my bike A Ribble A le, say's don't store it below 10 C or above 40 C. Generally I don't have to worry about the latter in the UK, well up until the heatwaves we are getting, it's the below 10 C in winter I tend to worry about. What US coastguard veteran said, I agree, if it's a scorcher such as 32 to 34 C, I just try not to put it on full assist, use sparingly. This may sound sad but at the moment in the heatwave we have in the UK, I am checking the Temp of the battery and Motor twice a day and recording it. If it's hot in the veranda, I shift it in to the shade in the kitchen or under a tree at the top of the garden until the outside temp drops.